this is how I ended up building the summon missile power and the homing missiles themselves. Let me know if there's a better way, or if I've done anything wrong.
the summon:
Summon 225-point Guided missile, 16 Charges (+0), Amicable Slavishly Devoted (+1) (90 Active Points)
The missile:
Val Char Cost
0 STR -10
38 DEX 84
0 CON -20
1 BODY -18
14 INT 4
0 EGO 0
0 PRE -10
0 COM -5
0 PD 0
0 ED 0
6 SPD 12
0 REC 0
0 END 0
0" RUN -12
0" SWIM -2
0" LEAP 0
Characteristics Cost: 23
Cost Power
45 Automaton (Takes No STUN (loses abilities when takes BODY))
10 Endurance Reserve (100 END, 0 REC)
56 Killing Attack - Hand-To-Hand 4d6 (vs. ED), Trigger: body damage (Misfire +1/4), Explosion (+1/2), Reduced Endurance 0 END (+1/2), Damage Shield (+1/2), Offensive (+1/4), Continuous (+1) (240 Active Points); Side Effects, Side Effect occurs automatically whenever Power is used (-2), No STR Bonus (-1/2), Only works with successful move-through (-1/2), Only full effect (-1/4)
12 +6 with Flight
50 Flight 40", Usable Underwater (+1/4) (100 Active Points); No deceleration (-1/2), No Noncombat Movement (-1/4), Only full effect (-1/4) (uses END Reserve)
24 Detect target 16-, Increased Arc of Perception: 360-Degree, Sense, Targeting Sense
5 Infrared Perception
Powers Cost: 202
Total Character Cost: 225
Pts. Disadvantage
100 Just a guided missile and all that that implies
Disadvantage Points: 100
Base Points: 125